Dentures are worn by a considerable number of individuals. The average life span of a denture is approximately seven years, although many individuals continue to wear dentures well beyond that time period. Additionally, dentures become ill-fitting over time due to changes in the patients anatomy. Dentures may also become damaged over time as well. Also, some individuals may want to have a spare denture in case of the loss of the original denture or in the event of an accidental fracture of their primary denture. The cost and time of creating a new denture can often be considerable. Thus, it is often desirable to make a new denture based on an existing denture, particularly if the patient is satisfied with their existing dentures.
The duplication of an existing denture is preferable in most circumstances as the transfer of the shape of the existing dentures maintain the neuromuscular control to the new dentures. Minor modifications are often necessary as well to compensate for worn teeth and denture bases and for changes in the patients anatomy.
There are a number of techniques currently available for providing a patient with a duplicate denture. Many times a temporary denture will be fabricated by the dentist for the patient while the new denture is being fabricated. However, these temporary dentures are usually ill-fitting, uncomfortable and not intended for continued use. Duplicate dentures are normally fabricated based on the prescription and information from the individual's original dentures, if available. Often, there may be a considerable amount of time that has elapsed and such information may not be available. So rather than create a new denture from scratch, it is often more sensible to duplicate a new denture from existing dentures.
There are a number of techniques currently available for duplicating existing dentures. These techniques involve producing a mold by inserting the existing denture into a rigid container such as a duplicating flask, dental flask or other container filled with an elastic material such as alginate or silicon putty. A wax or auto-polymerizing resin template is then fabricated from the mold. This template is tried in the patient's mouth and modifications are made if necessary. Then the final denture is made and provided to the patient. Other variations include forming a wax rim instead of the auto-polymerizing resin or using a silicon putty to create the denture base. These techniques require several try-ins to ensure the proper fit in the patient and the creation of initial templates or wax rims, then the actual denture. This entails considerable time and expense for the patient.